Control seeds were inoculated with 50 ll of sterile water. Petri dishes containing fungi- and/or bacteria-contaminated seeds were discarded. Bean seeds (variety Contender, Ferry-Morse Seed Co., Fulton, KY) were disinfested, incubated and treated as described for the cacao seeds, except that the incubation period was 4 days. Treated cacao and bean seeds were transferred either to sterile test tubes ( 200 ml) containing approximately 30 ml of 0.5% water–agar (sterile system) or to nonsterile 3-kg-pots filled with a mixture of sand, perlite, and potting soil (1:2:1) (nonsterile system). Pots were kept inside glass boxes and both pots and tubes were maintained under fluorescent light at 25 C in the laboratory.